A comparative study of thermo-physical properties of different nanofluids for effective heat transfer leading to Li-ion battery pack cooling

The rapid advancement in Lithium-ion battery technology has significantly boosted the electric vehicle market worldwide. These batteries are highly sought after by automobile manufacturers and researchers due to their exceptional energy storage and power capabilities. However, efficient working temperatures ranges from 15 degrees C to 35 degrees C, making it essential to implement battery cooling and heating methods to maintain optimal performance. This study primarily focuses on battery cooling. The automotive manufactures have focused on ethylene glycol, water and synthetic oils as commonly used coolants for keeping the lithium-ion battery pack within working temperature limits. However, these fluids have lower heat conduction, leading to reduced heat transfer rates and diminished cooling performance. To address this issue, nano-enhanced fluids, which are engineered fluids containing suspended nanospheres, have been explored. The heat transfer properties of conventional coolants are increased using nano-enhanced fluids, thereby improving heat conduction and promoting efficient heat transfer within the battery. The study compares the temperature-related characteristic of different nano-enhanced fluids, including oxides of copper (CuO), titanium (TiO2), aluminum (Al2O3), silicon (SiO2), and zinc (ZnO), when added to base fluids such as synthetic oils, water and ethylene glycol. The importance to capacity of specific heat, conductivity of fluid thermally, fluid resistance to flow and fluid volumetric mass which are affected by changes in temperature limits are stressed upon. Depending on the specific application and test conditions, the effectiveness of one nano-enhanced fluid may outperform the others. In conclusion, the thermo physical properties of nanofluids play a critical role in maintaining the battery pack temperature within operating temperature limits. The selections of nanofluids for particular battery thermal management system depends upon its arrangement along the battery pack and cell geometry. The cooling performance using nanofluids as coolant is 10% to 15% higher than the conventional used fluids. This nano-enhanced fluid show great promise in enhancing the cooling capabilities of battery cooling systems, contributing to improved Lithium-ion battery performance in electric vehicles.